Commercial shipping operations include movement of cargo using intermodal containers. A substantial amount of world cargo transport is completed using these intermodal containers. Presently cargo security is a major concern. One simple means to assure that cargo is shipped intact is to use a seal to secure the doors on a container. The concept here is that if the seal was put in place by a trusted source at an origin location, and it remains intact at an intended destination location that the cargo is intact and in fact safe. Prior art includes many types of mechanical seals. One problem with these mechanical seals is that they require manual inspection which is relatively expensive, inconvenient and slows down transport. Electronic seals using Radio Frequency Identification (RFID) technology are also available but are prohibitively costly and moreover complicated to use because operators need to be retrained to use this new technology. Also electronic seals are bulky devices because they contain relatively large antenna structures. As a result benefits of electronic seals, including readability while cargo is in motion, have not been realized.
What the intermodal container transport industry needs is an electronic seal that is simple to use without changing operator convention.